Standard versus bony increased-offset reverse shoulder arthroplasty: a retrospective comparative cohort study

Area of Science:

• Orthopedic surgery
• Shoulder arthroplasty
• Biomechanical engineering

Background:

• Limited comparative studies exist between traditional reverse shoulder arthroplasty (tRSA) and bony increased-offset RSA (BIO-RSA).
• Previous research suggests potential benefits of BIO-RSA, prompting further investigation.

Purpose of the Study:

• To compare the clinical outcomes and radiographic findings of BIO-RSA versus tRSA.
• To evaluate differences in range of motion (ROM), Constant scores, and scapular notching rates.

Main Methods:

• Retrospective review of 69 tRSAs and 61 BIO-RSAs performed by a single surgeon.
• Comparison of ROM and Constant scores at 2-year postoperative follow-up.
• Radiographic assessment for scapular notching, spurring, ossification, and graft healing.

Main Results:

• BIO-RSA demonstrated improved anterior forward flexion (145° ± 20° vs. 138° ± 20°, P=.017) and higher Constant scores (69 ± 9 vs. 61 ± 13, P<.001) compared to tRSA.
• No significant differences were observed in external/internal rotation or scapular notching rates between the groups.
• Radiographic findings, including graft healing, were comparable between BIO-RSA and tRSA.

Conclusions:

• At 2-year follow-up, BIO-RSA did not yield clinically significant improvements in ROM, Constant scores, or scapular notching compared to tRSA.
• The study suggests that the benefits of BIO-RSA may not outweigh those of tRSA in terms of these specific outcomes.
• Further research with larger sample sizes may be warranted to explore long-term differences.